Ratepayers face having to bankroll most of Christchurch's planned new civic facilities after the city council was given a clear message by the Government that it will not pick up the tab.

While the Government is happy to take the lead on some projects, such as the new emergency and justice precinct, it expects the council to drive the construction of facilities like the new sports stadium, convention centre and metro sports facility.

Council corporate services manager Paul Anderson said discussions over the past few weeks with the Canterbury Earthquake Recovery Authority (Cera) had led the council to pledge up to $155 million on top of what was already decided on. That would bring its total commitment to $787m. The $155m, however, still needed to be signed off by councillors.

Prime Minister John Key has said the funding for the civic assets would need to be worked out between the Christchurch City Council and the private sector.

The extra financial burden comes after the council already had to lift rates this year by 7.8 per cent to help pay for the cost of rebuilding quake-damaged infrastructure.

It now faces having to find money for a bigger convention centre (up from a planned 21,000 square metres to 24,000sqm) and a bigger sports stadium (up from 30,000 to 35,000 capacity) than it wanted, a new library (it was planning on rebuilding the old one) and a new metro sports facility.

Earthquake Recovery Minister Gerry Brownlee acknowledged yesterday the council was going to have to find a lot of funds, but said it did have options to deal with that.

At a breakfast for more than 200 businesspeople Brownlee stopped short of directly calling on the council to sell or partly sell off some of its assets, but he alluded to it by congratulating the Canterbury Employers' Chamber of Commerce for putting options on the table that he thought the council should consider.

The business group has been encouraging the council to consider the sale or partial selldown of its assets. Cr Helen Broughton, chairwoman of the council's corporate and financial committee, said the council had $787m it was prepared to commit at this stage to the central city rebuild but it might need to find more.

"I don't think councillors will want to go higher than that," she said.

"There's a lot more negotiation to be done on some of the projects."

Cr Tim Carter said the full implications of the blueprint had yet to be discussed by the council so he could not speculate on the extent of its financial burden. But he said the council might need to discuss with the community the option of asset sales.

"In principle I'm against asset sales but we are going to have to sit down and look at our obligations and discuss it with the community and see what they want us to do."

Green MP Eugenie Sage said yesterday she had asked under the Official Information Act for the Treasury report detailing the Government's discussions with the council about funding for the central city rebuild, but what she got back was a document with nearly every word, bar the title, blacked out.

"We need to ensure that we can afford what is proposed without putting pressure on the city council to sell our well performing assets," Sage said.

Christchurch International Airport, Orion and Lyttelton Port of Christchurch were strategic and regionally important assets. The dividends and revenue stream they provided helped the council to keep Christchurch rates low.